Lesson 2-1You only see the Moon because light from the Sun reflects off the Moon and into your eyes.

Seeing the Moon

Lesson 2-2According to the giant impact hypothesis, shortly after Earth formed about 4.6 billion years ago, an object about the size of the planet Mars collided with Earth.

The Moon’s Formation

Lesson 2-2The impact ejected vaporized rock that formed a ring around Earth.

The Moon’s Formation (cont.)

Lesson 2-2Eventually, the material in the ring cooled and clumped together and formed the Moon.

The Moon’s Formation (cont.)

Lesson 2-2• The surface of the Moon was shaped early in its

history.

• Moon’s craters were formed when objects from space crashed into the Moon.

The Moon’s Formation (cont.)

Lesson 2-2The large, dark, flat areas on the Moon are calledmaria.

The Moon’s Formation (cont.)

Lesson 2-2• When the maria formed, lava flowed up through

the Moon’s crust and solidified, covering many of the Moon’s craters and other features.

• The light-colored highlands are too high for the lava that formed the maria to reach.

The Moon’s Formation (cont.)

Lesson 2-3• The Moon rotates as it revolves around Earth.

• One complete rotation of the Moon takes 27.3 days, meaning the Moon makes one rotation in the same amount of time that it makes one revolution around Earth.

The Moon’s Motion

Lesson 2-3• Because the Moon takes the same amount of

time to orbit Earth and make one rotation, the same side of the Moon is always facing Earth.

• This side of the Moon is called the near side.

• The side of the Moon that cannot be see from Earth is called the far side of the moon.

The Moon’s Motion (cont.)

Lesson 2-3The Moon’s Motion (cont.)

Draw this diagram with flags and arrows on following pages: Periods 1,3,7- NB 45, Periods 2,4,5- NB 37

Lesson 2-4The lit part of the Moon or a planet that can be seen from Earth is called a phase.

Phases of the Moon

Lesson 2-4The motion of the Moon around Earth causes the phase of the Moon to change.

Jason Reed/Photodisc/Getty Images

Lesson 2-4

Draw this Diagram and label each phase of the moon- Periods 1,3,7- NB 45, Periods 2,4,5- NB 37

Lesson 2-4• The sequences of phases is the lunar cycle.

• During the waxing phases, more of the Moon’s near side is lit each night.

• During the waning phases, less of the Moon’s near side is lit each night.

Phases of the Moon (cont.)

Lesson 2-5Phases of the Moon (cont.)